Materials
at the nanoscale offer numerous avenues to be explored
and exploited in diverse realms. Among others, proteinaceous biomaterials
such as silk hold immense prospects in the domain of nanoengineering.
Silk offers a unique combination of desirable facets like biocompatibility;
extraordinary mechanical properties, such as elongation, elasticity,
toughness, and modulus; and tunable biodegradability which are far
better than most naturally occurring and engineered materials. Much
of these properties are due to the molecular structure of the silk
protein and it is self-assembly into hierarchical structures. Taking
advantage of the hierarchical assembly, a large number of fabrication
strategies have now emerged that allow the tailoring of silk structure
of at the nanoscale. Harnessing the favorable properties of silk,
such methods offer a promising direction toward producing structurally
and functionally optimized silk nanomaterials. This review discusses
the critical structure–property relationship in silk that occurs
at the nanoscale and also aims to bring out the recent status in the
approaches for fabrication, characterization, and the gamut of applications
of various silk-based nanomaterials (nanoparticles, nanofibers, and
nanocomposites) in the niche of translational research. Harnessing
the favorable nanostructure of silk, the review also takes into account
the impetus of silk in avant-garde applications such
as chemo-biosensing, energy harvesting, microfluidics, and environmental
applications.